Karl has answered it pretty well. - I think "or is it" raises doubt that you are unsure or you want to raise a different perspective. Examples: 1) Girlfriend: "It's time to start working!" Boyfriend: ”Or is it?“ *starts to goof off and have fun* 2) "This is a hard question, or is it?" ( I think this problem is hard but it could actually be easy. I'm not sure ) - "what if we were to embrace the concept......" You cannot omit "we were" but you could omit "were to" in this instance. "what if we embrace..." and "what if we were to embrace" is correct. Perhaps an English major can tell you the difference in meaning between these two.

"Life must just be so unfair to us, or is it?" The first part of the sentence is a statement, and the second part is raising doubt about that statement. So the entire sentence is showing that the person doesn't really know what to believe. They begin by saying "life MUST just be so unfair to us", but they turn this statement into a question by adding "OR is it?". Then the next sentence goes a bit further by asking the question - "What if....WE are the ones getting in the way of reaching our goals?". Do you see? If we are the ones getting in the way, then we can't say that life is unfair. Unfairness is when something bad happens to you for no good reason. The second question about "we were" is a grammatical question and a proper English teacher could answer it better than I, but yes, you can omit it and say "What if we embrace the concept...". This would not change the meaning of the sentence in any substantial way. I will say that the phrase "What if we were..." is common, and we use it when we want to express the fact that we are trying to decide what to do in the future.

I guess that 'or is it' is equivalent to 是不是. You can't omit 'we were'. You can omit 'were to'.